IUCr journals

Experimental lensless soft-X-ray imaging using iterative algorithms: phasing diffuse scattering

Acta Cryst. (2003). A59, 143–152

[Gold balls] Clusters of gold balls, 50 nm diameter, imaged using soft x-rays. Image obtained using iterative algorithm to solve the phase problem. Resolution about 10 nm.

Phase information is encoded in diffuse x-ray scattering from nonperiodic objects if it is sampled finely enough. The Fienup HiO iterative algorithm has proven the most successful method of extracting it. We record soft x-ray (λ = 2.1 nm) transmission speckle patterns from clusters of 50 nm diameter gold balls lying on a transparent substrate. We use the HiO algorithm to solve the phase problem and so reconstruct images of the balls. The presence of an isolated ball also produces a faithful image in the Patterson map. A reconstructed image is shown to the right. Beam stops, absorption filters, density modification and Fourier transform holography are also discussed.

H. He, S. Marchesini, M. Howells, U. Weierstall, G. Hembree and J.C.H. Spence